Wireless local area network channel resource management

ABSTRACT

A wired Local Area Network (wired LAN) and a plurality of Wireless Access Points (WAPs) coupled to a wired network infrastructure of the wired LAN service wireless packetized communications for a plurality of Wireless Local Area Network (WLAN) clients. A multi-layer switch of the wired LAN identifies a WLAN client serviced by a WAP from the packetized communications, and upon receiving an overloading indication from the WAP, determines that the WLAN client serviced by the WAP exceeds a usage threshold. Based upon the determination, the multi-layer switch reduces the wireless bandwidth provided to the wireless terminal by the WAP.

CROSS REFERENCE TO RELATED APPLICATIONS

The present U.S. Utility patent application claims priority pursuant to35 U.S.C. § 120, as a continuation, to the following U.S. Utility patentapplication which is hereby incorporated herein by reference in itsentirety and made part of the present U.S. Utility patent applicationfor all purposes:

1. U.S. Utility application Ser. No. 10/271,966, entitled “WirelessLocal Area Network Channel Resource Management,” (Attorney Docket No.BP2152.1), filed Oct. 15, 2002, pending, which claims priority pursuantto 35 U.S.C. § 119(e) to the following U.S. Provisional PatentApplication which is hereby incorporated herein by reference in itsentirety and made part of the present U.S. Utility patent applicationfor all purposes:

a. U.S. Provisional Application Ser. No. 60/342,684, entitled “WirelessLocal Area Network Channel Resource Management,” (Attorney Docket No.BP2152.1), filed Dec. 21, 2001, expired.

1. FIELD OF THE INVENTION

This invention relates generally to the merging of wired and wirelesslocal area networks; and more particularly to the management of wirelesslocal area network components within a merged network.

2. BACKGROUND OF THE INVENTION

Communication technologies that link electronic devices in a networkedfashion are well known. Examples of communication networks include wiredpacket data networks, wireless packet data networks, wired telephonenetworks, wireless telephone networks, and satellite communicationnetworks, among other networks. These communication networks typicallyinclude a network infrastructure that services a plurality of clientdevices. The Public Switched Telephone Network (PSTN) is probably thebest-known communication network that has been in existence for manyyears. The Internet is another well-known example of a communicationnetwork that has also been in existence for a number of years. Thesecommunication networks enable client devices to communicate with oneanother other on a global basis. Wired Local Area Networks (wired LANs),e.g., Ethernets, are also quite common and support communicationsbetween networked computers and other devices within a serviced area.Wired LANs also often link serviced devices to Wide Area Networks andthe Internet. Each of these networks is generally considered a “wired”network, even though some of these networks, e.g., the PSTN, may includesome transmission paths that are serviced by wireless links.

Wireless networks have been in existence for a relatively shorterperiod. Cellular telephone networks, wireless LANs (WLANs), andsatellite communication networks, among others, are examples of wirelessnetworks. Relatively common forms of WLANs are IEEE 802.11(a) networks,IEEE 802.11(b) networks, and IEEE 802.11(g) networks, referred tojointly as “IEEE 802.11 networks.” In a typical IEEE 802.11 network, awired backbone couples to a plurality of Wireless Access Points (WAPs),each of which supports wireless communications with computers and otherwireless terminals that include compatible wireless interfaces within aserviced area. The wired backbone couples the WAPs of the IEEE 802.11network to other networks, both wired and wireless, and allows servicedwireless terminals to communicate with devices external to the IEEE802.11 network.

WLANs provide significant advantages when servicing portable devicessuch as portable computers, portable data terminals, and other devicesthat are not typically stationary and able to access a wired LANconnection. However, WLANs provide relatively low data rate service ascompared to wired LANs, e.g., IEEE 802.3 networks. Currently deployedwired LANs provide up to one Gigabit/second bandwidth and relativelysoon, wired LANs will provide up to 10 Gigabit/second bandwidths.However, because of their advantages in servicing portable devices,WLANs are often deployed so that they support wireless communications ina service area that overlays with the service area of a wired LAN. Insuch installations, devices that are primarily stationary, e.g., desktopcomputers, couple to the wired LAN while devices that are primarilymobile, e.g., laptop computers, couple to the WLAN. The laptop computer,however, may also have a wired LAN connection that it uses when dockedto obtain relatively higher bandwidth service.

Other devices may also use the WLAN to service their communicationneeds. One such device is a WLAN phone, e.g., an IEEE 802.11 phone thatuses the WLAN to service its voice communications. The WLANcommunicatively couples the IEEE 802.11 phone to other phones across thePSTN, other phones across the Internet, other IEEE 802.11 phones, and/orto other phones via various communication paths. IEEE 802.11 phonesprovide excellent voice quality and may be used in all areas serviced bythe WLAN.

Significant problems exist, however, when using a WLAN to support voicecommunications. Because the WLAN services both voice and datacommunications, the WLAN may not have sufficient capacity to satisfy thelow-latency requirements of the voice communication. These capacitylimitations are oftentimes exacerbated by channel limitations imposed inmany IEEE 802.11 installations. Further, roaming within a WLAN (betweenWAPs) can introduce significant gaps in service, such gaps in serviceviolating the low-latency requirements of the voice communication.

Each WAP of the WLAN has a limited supported wireless bandwidth thatmust service each wireless terminal within a respective service area.When a single wireless terminal accesses the WAP, it may consume arelatively large portion of the WAP's wireless bandwidth. Such heavyusage by a single wireless terminal reduces the wireless bandwidth thatmay be used by other wireless terminals operating within the respectiveservice area, thus degrading their service.

Thus, there is a need in the art for improvements in the operation andmanagement of WLANs, particularly when the WLANs are installedadditionally to wired LANs.

SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Invention, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will be more fully understood when considered with respect tothe following detailed description, appended claims and accompanyingdrawings wherein:

FIG. 1 is a system diagram illustrating a premises in which a networkconstructed according to the present invention is deployed;

FIG. 2 is a system diagram illustrating a premises based networkconstructed according to the present invention that supports both wiredlocal area network and wireless local area network operations;

FIG. 3 is a partial system diagram illustrating a portion of a campus inwhich wireless communications are serviced according to the presentinvention;

FIG. 4 is a block diagram partially illustrating a portion of a networkof FIG. 3 that supports operations according to the present invention;

FIG. 5 is a block diagram illustrating two manners in which Class ofService information may be incorporated into data packets according tothe present invention;

FIG. 6 is a block diagram illustrating a multi-layer switch constructedaccording to the present invention;

FIG. 7 is a block diagram illustrating a Wireless Access Pointconstructed according to the present invention;

FIG. 8 is a logic diagram illustrating operation of the multi-layerswitch of FIG. 6 according to the present invention;

FIG. 9 is a logic diagram illustrating one embodiment of operation ofFIG. 8 in which the multi-layer switch of FIG. 6 determines whether toand the manner in which wireless terminal access to a WAP is adjusted;and

FIG. 10 is a logic diagram illustrating one technique for adjusting theaccess of a wireless terminal to a servicing WAP by increasingrespective packetized communication delay.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system diagram illustrating a premises 100 in which anetwork constructed according to the present invention is deployed. Thepremises 100 (campus) includes office buildings 102, 104, 106 andindustrial buildings 108, 110, 112, and 114. The premises 100 maycorrespond to a company such as a technology company, a seller of goods,a service company, or another type of company. Contained within each ofthe office buildings 102, 104, and 106 are a number of offices, each ofwhich provides a working space for at least one person. Each of theindustrial buildings 108, 110, 112, and 114 provides space formanufacturing, storage, or another purpose. People also work withinindustrial buildings 108, 110, 112, and 114.

Contained within each of these buildings 102-114 are computerworkstations, computer servers, printers, FAX machines, phones, andother electronic devices. Each of these electronic devices has itscommunication requirements. For example, computer workstations, computerservers, and printers each require data communication service. Such datacommunication service requires that the devices can communicate withother devices located within the premises 100 and with devices locatedexternal to the premises 100 across one or more data networks. The FAXmachines and phones require coupling to one another and to the PublicSwitched Telephone Network (PSTN).

According to the present invention, both wired and wirelesscommunications are supported within the premises 100 via a network thatprovides both wired Local Area Network (wired LAN) and Wireless LocalArea Network (WLAN) functionality. The manner in which the network isconstructed and the manner in which the wired LAN and WLAN functionalityare provided are described further with reference to FIGS. 2 through 10.

FIG. 2 is a system diagram illustrating a premises based networkconstructed according to the present invention that supports both wiredLAN and WLAN operations. Illustrated in FIG. 2 are some of thecomponents of the network infrastructure that support the premises 100of FIG. 1. The network includes a pair of campus core routers 200A and200B that redundantly service the premises 100. Both of the campus corerouters 200A and 200B couple to the PSTN 210, via an Inter WorkingFunction “IWF” in some embodiments. Both of the campus core routers 200Aand 200B also couple to the Internet 212, via a Gateway or Firewall 214in some embodiments. As is generally known, the PSTN 210 servicesconventional voice communications but may also service packet datacommunications, e.g., Digital Subscriber Lines, etc. The Internet 212services most packet data communications for the premises 100 and mayservice Internet Protocol (IP) telephony as well. As should beappreciated by the reader, the campus core routers 200A and 200B maycouple to other networks across the Internet 212 or via dedicatednetwork connections.

Each building serviced by the network includes its own building networkinfrastructure. Each building network infrastructure includes componentscontained within dotted lines 202A and 202B, for example. Each of theoffice buildings 102, 104, and 106 shown in FIG. 1 includes a buildingnetwork infrastructure. The building network infrastructure 202Aincludes building/floor routers 204A and 204B that service a pluralityof wired network switches/hubs 208A and 208B and a plurality of WirelessAccess Points (WAPs) 206A and 206B. The communication links between thebuilding/floor routers 204A and 204B and the campus core routers 200Aand 200B are typically at a relatively high data rate, e.g., 1000 Mbps.The communication links between the building/floor routers 204A and 204Band the WAPs 206A and 206B and the switches/hubs 208A and 208B are alsotypically at the relatively high data. However, client connections tothe switches/hubs 208A and 208B are typically at a relatively lower datarate, e.g., 100 Mbps or 10 Mbps. The building network infrastructure202B services another building and includes building/floor routers 204Cand 204C, switches/hubs 208C and 208D, and WAPs 206C and 206D.

The switches/hubs 208A-208D service a plurality of wired LAN clients,e.g., desktop computers, wired phones, and other wired LAN devices. TheWAPs 206A-206D service wireless network clients, e.g., laptop computers,wireless terminals, but may also service other devices that cannoteasily access a wired LAN plug, such as a desktop computer. The WAPs206A-260D may operate according to a standardized communicationprotocol, e.g., IEEE 802.11(a), IEEE 802.11(b), IEEE 802.11(g), etc. Incombination, these devices service most, if not all of the packetcommunications within the premises 100 of FIG. 1. Of course, thestructure of FIG. 2 is an example only and an actual implementationwould include substantially more equipment and more links.

At least one network manager 218 and at least one database 220 couple tothe campus core router 200B and/or the campus core router 200A. As willbe further described herein, the network manager 218 operates incooperation with the campus core routers 200A and 200B and/or thebuilding floor routers 204A-204B to manage access to the WAPs 206A-206D.While the database 220 and the network manager 218 are shown to resideexternal to the campus core routers 200A, the components could also belocated within a common housing and/or be implemented by the processingcomponents of the campus core routers 200A. Further, the database andthe network manager 218 may not couple directly to the campus corerouter 200A but may coupled indirectly thereto.

The campus core routers 200A and 200B and/or the building/floor routers204A, 204B, 204C and/or 204C support Wireless Access Point (WAP)management according to the present invention. The campus core routers200A and 200B and/or the building/floor routers 204A, 204B, 204C and/or204C are referred to as multi-layer switches further herein and themanagement operations that they perform are described further withreference to FIGS. 3 through 10. These operations are typicallyimplemented in software but may be implemented partially in software andpartially in hardware.

FIG. 3 is a partial system diagram illustrating a portion of a campus inwhich wireless communications are serviced according to the presentinvention. A building floor 300 shown in FIG. 3 is part of the campusand may be a lower floor of one of the buildings of FIG. 1, e.g.,building 102. The building floor 300 includes a plurality of rooms 302,304, 306, and 308. Each of these rooms 302, 304, 306, and 308 includes aWAP 206A, 206B, 206C, and 206D, respectively, that services acorresponding area. Further, an external WAP 206E provides serviceexternal to room 308 of building floor 300. Each of these WAPs 206A-206Ecouples to a servicing building/floor router 204A or 204B via the wiredLAN backbone. The servicing building/floor router 204A or 204B couplesto the campus core router 200A (or 200B) as shown in FIG. 2.

Serviced within the building floor 300 are wireless terminals 312A-312Iand laptop computers 314A-314H. Each of these devices wirelesslycommunicates with a servicing WAP. For example, laptop computer 314A andwireless terminals 312A and 312B wirelessly communicate with WAP 206A(in their illustrated positions). Each of the WAPs 206A-206D supportswireless communications primarily within a designated area, rooms302-308, respectively. However, the coverage area of each WAP 206A-206Dextends beyond the boundaries of its respective rooms 302-308 so thatoverlapping coverage areas exist. For example, WAPs 206A and 206Cprovide service between rooms 302 and 306 so that wireless terminalsthat roam between the rooms continue to receive wireless communicationservice when between the rooms 302 and 306. Further, WAP 206E supportswireless communications outside of the floor 300 to service laptopcomputer 314H and wireless terminal 312I. Note that the WAP placement ofFIG. 3 is an example only and that each room may contain multiple WAPsor that a single WAP may cover multiple rooms.

FIG. 4 is a block diagram partially illustrating a portion of a networkof FIG. 3 that supports operations according to the present invention.The portion of the network shown includes WAPs 206A and 206B thatsupport wireless communications within a jointly serviced area, forexample, the rooms 302 and 304 of FIG. 3. The WAPs 206A and 206B coupleto the network infrastructure 405, e.g., the network infrastructureshown in FIG. 2. The WAPs 206A and 206B service wireless communicationsfor laptop computers 406, 408, and 410, desktop computers 412, 414, 416,and 418, and wireless terminals 420, 422, 422, 424, 426, and 428. Theservice coverage areas provided by WAPs 206A and 206B partially overlap.The network infrastructure 405 couples to one or more servicingmulti-layer switches, e.g., campus core router 200A that includes WAPmanagement functionality according to the present invention.

According to one aspect of the present invention, the operation of theplurality of WAPs 206A and 206B are partially managed by a core router,e.g., campus core router 200A, to ensure that that no single servicedwireless terminal consumes all or a significant portion of the bandwidthof the WAP. Today, 802.11 networks service at most data rates of 11Mbps. This data rate translates into a more typical data rate of 5.5Mbps or less at protocol layer 4. Further, Bit Error Rates (BERs) of802.11 networks are generally 100 times worse than BERs of wired LANs.Thus, wireless capacity supported by each WAP is quite scarce. Accordingto the present invention, WAPs and multi-layer switches that support theWAPs perform flow control on all wireless terminals to ensure that nosingle user consumes a disproportionate amount of the availablebandwidth of the WAP.

In performing WAP resource management, a managing device, e.g.,multi-layer switch 200A and/or network manger 218 automatically detectsa wireless terminal that is exceeding a permissible bandwidth usage of aWAP. The managing device then intervenes to limit the wireless bandwidthused by the wireless terminal. One technique used by the managing devicefor limiting bandwidth usage is to slow the operation of input andoutput buffer queues to thereby limit the rate at which TCPacknowledgements occur. With this reduction in TCP acknowledgement rate,the data rate at the TCP layer is reduced and therefore the offendingdevice uses less wireless bandwidth. Another technique used by themanaging device is to reduce a Class of Service (CoS) provided to thewireless terminal by the WAP. These operations are described in detailwith particular reference to FIGS. 8-10.

FIG. 5 is a block diagram illustrating two manners in which Class ofService information may be incorporated into data packets according tothe present invention. In one operation of the present invention, amulti-layer switch, e.g., campus core router 200A, alters the CoS ofpacketized communications to alter the manner in which a servicing WAPprocesses the packetized communication. If a wireless terminal/WLANclient is consuming a disproportionate amount of the resources of theWAP, the campus core router 200A may reduce the CoS of packets for thewireless terminal/WLAN client that it forwards to the WAP. In such case,the WAP would then provide a lesser grade of service to the wirelessterminal/WLAN client, thus reducing the WAP resources being consumed bythe wireless terminal/WLAN client.

FIG. 6 is a block diagram illustrating a multi-layer switch, e.g.,campus core router 200A (or 200B) or building/floor router 204A-204Dconstructed according to the present invention. The structureillustrated in FIG. 6 is a diagrammatic representation of the structureof the multi-layer switch of FIG. 2 with minimal detail. As the readerwill appreciate, other structures will support operation according tothe present invention and the structure of FIG. 6 is only one example ofthe structure of a multi-layer switch. The multi-layer switch 200Aincludes a processor 602, memory 604, storage 606, a high-speedinterface 608, and a port interface 612, all of which couple via asystem bus 614. Also contained within the multi-layer switch 200A is apacket switch 610 that couples to high-speed interface 608, portinterface 612, and the system bus 614. The high-speed interface 608either couples to a plurality of data networks or couples redundantly toa single data network. These interconnections are designated to be fiberinterconnections. However, the interconnections could also be wiredconnections. With the structure of FIG. 2, for example, the high-speedinterface 608 couples the multi-layer switch 200A to the gateway 214 andto the IWF 216. The port interface 612 includes eight ports and couplesthe multi-layer switch 200A to the wired network infrastructure of theLAN. Other embodiments of the port interface 612 of the multi-layerswitch 200A may include a greater number, or a lesser number of ports.

In order to operate according to the present invention, the multi-layerswitch 200A performs software and/or hardware operations. Theinstructions and operations that cause the multi-layer switch 200A tooperate according to the present invention are referred to as WAPManagement Instructions (WMI). When the WMI are implemented as softwareinstructions, WMI are initially stored as WMI 616 in storage 606. Thestorage 606 may be an optical media, a hard drive, or othersubstantially static storage device. Memory 604 may include dynamicrandom access memory, read-only memory, or another type of memory thatis known in the arts to facilitate the storage of instructions and dataand that may be accessed by processor 602. Processor 602 may be a singlemicroprocessor, multiple microprocessors, a processing module, oranother processing device that is capable of executing softwareinstructions and controlling the operation of other multi-layer switch200A components coupled via system bus 614.

In executing the WMI 616, the WMI 616 are copied from storage 606 tomemory 604 as WMI 618 and then read by the processor 602 from memory 604as WMI 620. The execution of the WMI 620 by the processor 602 causes theprocessor to program/control the operation of the port interface 612 tooperate according to the present invention. The processor 602 may thenconfigure WMI 622 in the port interface 612 and/or WMI 623 in the packetswitch 610. Such configuration may include programming routing tableswith values and parameters. In combination, the WMI operations 620performed by the processor, the WMI 622 performed by the port interface612, and the WMI 623 performed by the packet switch enable themulti-layer switch 200A to operate according of the present invention.

FIG. 7 is a block diagram illustrating a Wireless Access Point (WAP)106A, 106B, 106C, or 106D constructed according to the presentinvention. The WAP 106A includes a processor 704, dynamic RAM 706,static RAM 708, EPROM 710, and at least one data storage device 712,such as a hard drive, optical drive, tape drive, etc. These components(which may be contained on a peripheral processing card or module)intercouple via a local bus 717 and couple to a peripheral bus 720 viaan interface 718.

Various peripheral cards couple to the peripheral bus 720. Theseperipheral cards include a network infrastructure interface card 724,which couples the WAP 103 to its servicing building/floor router (orcore router). Baseband processing cards 726, 728 and 730 couple to RadioFrequency (RF) units 732, 734, and 736, respectively. Each of thesebaseband processing cards 726, 728, and 730 performs digital processingfor a respective wireless communication protocol, e.g., 802.11(a),802.11(b), and 802.11(g), serviced by the WAP 206A. The RF units 732,734, and 736 couple to antennas 742, 744, and 746, respectively, andsupport wireless communication between the WAP 103 and wirelesssubscriber units. The WAP 103 may include other card(s) 740 as well.While the WAP 206A illustrated in FIG. 7 is shown to support threeseparate wireless communication protocols, other embodiments of the WAP206A could support one, two, or more than three communication protocols.

The WAP 206A performs operations according to the present invention thatare embodied at least partially as software instructions, i.e., WMI. WMI714 enable the WAP 206A to perform the operations of the presentinvention. The WMI 716 are loaded into the storage unit 712 and some orall of the WMI 714 are loaded into the processor 704 for execution.During this process, some of the WMI 716 may be loaded into the DRAM706.

FIG. 8 is a logic diagram illustrating operation of the multi-layerswitch of FIG. 6 according to the present invention. Operation commenceswherein the multi-layer switch identifies a packetized communicationserviced by the WLAN (step 802). Because the multi-layer switch servicesboth wired LAN and WLAN operations, the multi-layer switch identifiesthe packetized communication as being serviced by the WLAN via either asource/destination of the packetized communication as corresponding to aWLAN client, a WLAN tag contained in the packetized communication, or byother means. Then, the multi-layer switch identifies a servicing WAP(step 804). The servicing WAP is one of a plurality of WAPs serviced bythe combined wired LAN and WLAN. Next, the multi-layer switch identifiesthe serviced WLAN client/wireless terminal (step 806). Each of theseidentification operations is performed by extracting information fromthe packetized communication and, in some operations, by comparingextracted information to information stored on the multi-layer switch.The multi-layer switch then stores the information that has beenobtained via investigation of the packetized communication. Thisinformation may be stored locally at the multi-layer switch or may bestored at the network manager 218 or the database 220.

Periodically, after each packetized communication investigation, or uponthe triggering of an overloading threshold, the multi-layer switch ornetwork manager determines whether a loading threshold is met for one ormore of the managed WAPs (step 810). These operations are described inmore detail with reference to FIG. 9. If a loading threshold is not met,operation returns to step 802. However, if a loading threshold is met,the multi-layer switch or the network manager adjusts the access of oneor more WLAN clients/wireless terminals to their servicing WAPs. Onetechnique for adjusting access is to alter the CoS provided to thewireless terminal. Another technique, which is described with referenceto FIG. 10, is to alter the rate at which higher layer protocols, e.g.,TCP layer, apply data.

RMON Ethernet standardized operations may be employed to perform theoperations of FIG. 8. RMON is a Management Information Base (MIB)Ethernet standard that defines current and historical MAC-layerstatistics and control objects, allowing real-time information captureacross an entire Ethernet based network. The RMON standard is an SNMPMIB definition described in RFC 1757 (formerly 1271) for Ethernet. TheRMON MIB provides a standard method to monitor the basic operations ofthe Ethernet, providing inoperability between SNMP management stationsand monitoring agents. RMON also provides a powerful alarm and eventmechanism for setting thresholds and for notifying you of changes innetwork behavior.

RMON is used to analyze and monitor network traffic data within remoteLAN segments from a central location. RMON is used according to thepresent invention to detect unfair usage of WAP resources. In someembodiments, RMON automatic histories are set up on one or moremulti-layer switches to collect traffic data over a period and to reportthe traffic data to the network manager. The network manager thenperiodically retrieves histories and adjusts the access ofclients/wireless terminals to WAP resources as described in FIG. 8.

FIG. 9 is a logic diagram illustrating one embodiment of operation ofFIG. 8 in which the multi-layer switch of FIG. 6 determines whether toand the manner in which wireless terminal access to a WAP is adjusted.The operations of FIG. 9 may be performed after information relating toa packetized communication serviced by the WAP is collected,periodically for each WAP, or upon the triggering of a loading event,e.g., overloading indication from a WAP. Usage thresholds may bedetermined periodically or based upon the real-time usage of a WAP (step902). Usage thresholds for each WAP consider the level of usage thateach wireless terminal is allowed, e.g., a percentage of availableresources, a data rate per unit time, or another measure of the wirelessterminal's usage of the wireless resources of a WAP.

Next, the actual usage of a WLAN client/wireless terminal is compared toa respective usage threshold (step 904). If this comparison isunfavorable (as determined at step 906), an adjustment for the WLANclient/wireless terminal is then determined (step 908). If thecomparison for the WLAN client/wireless terminal is not unfavorable, itis determined whether the current WLAN client/wireless terminal is thelast for consideration (step 910). If so, operation proceeds to step 812of FIG. 8. If not, a next WLAN client/wireless terminal is selected forcomparison (step 912) and operation returns to step 904.

FIG. 10 is a logic diagram illustrating one technique for adjusting theaccess of a wireless terminal to a servicing WAP by increasingrespective packetized communication delay. The packetized communicationsin which delay is to be added and the amount of delay to be added intosuch packetized communications were determined at step 908 of FIG. 9based upon estimates of how added delay will affect loading on servicingWAPs.

With the operations of FIG. 10, a multi-layer switch receives apacketized communication that is serviced by the WLAN (step 1002). Themulti-layer switch identifies the packetized communicationsource/destination (step 1004). The source/destination may be a WLANclient/wireless terminal serviced by a WAP of the WLAN. If so, and ifdelay is required (as determined at step 1006), the packetizedcommunication is buffered by the multi-layer switch for a delay period(step 1010). After the delay period has expired (at step 1012), themulti-layer switch forwards the packetized communication (step 1014).From step 1014, operation returns to step 1002.

The packetized communication may be either received from or directed tothe serviced WLAN client/wireless terminal. In either case, by delayingthe packetized communications, TCP layers operation on the WLANclient/wireless terminal or on its communication partner will observe anincreased round trip delay for the communication. With the increasedround trip delay, the TCP layers will reduce the rate at which theyapply packetized communications to the communication link. With thereduced rate of application, loading on the servicing WAP will decreasefor the particular WLAN client/wireless terminal.

The invention disclosed herein is susceptible to various modificationsand alternative forms. Specific embodiments therefore have been shown byway of example in the drawings and detailed description. It should beunderstood, however, that the drawings and description thereto are notintended to limit the invention to the particular form disclosed, but onthe contrary, the invention is to cover all modifications, equivalentsand alternatives falling within the spirit and scope of the presentinvention as defined by the claims.

1. A method for servicing Wireless Local Area Network (WLAN) clients bya wired Local Area Network (wired LAN) and a plurality of WirelessAccess Points (WAPs), the method comprising: wirelessly servicing, by aWAP of the plurality of WAPs and a multi-layer switch of the wired LAN,packetized communications for a plurality of WLAN clients; identifying,by the multi-layer switch, a WLAN client serviced by the WAP from thepacketized communications; receiving, at the multi-layer switch, anoverloading indication from the WAP; determining, by the multi-layerswitch, whether the WLAN client serviced by the WAP exceeds a usagethreshold; and if so, reducing the wireless bandwidth provided to theWLAN client by the WAP.
 2. The method of claim 1, wherein reducing thewireless bandwidth provided to the WLAN client by reducing a Class ofService (CoS) provided to the WLAN client by the WAP.
 3. The method ofclaim 1, wherein reducing the wireless bandwidth provided to the WLANclient by the WAP includes introducing round trip delay into packetizedcommunications serviced by the multi-layer switch to reduce the rate atwhich corresponding higher layer communication protocols apply data. 4.The method of claim 3, wherein introducing round trip delay causes a TCPlayer corresponding to the WLAN to reduce its rate of data applicationto corresponding lower layer protocols.
 5. The method of claim 1,wherein in determining that the WLAN client serviced by the WAP exceedsa usage threshold, the method includes: determining a usage thresholdfor the WLAN client; comparing a current usage level of the WLAN clientto the usage threshold for the WLAN client; and when the comparison isunfavorable, concluding that the WLAN client serviced by the WAP exceedsthe usage threshold.
 6. The method of claim 1, wherein identifying, bythe multi-layer switch, the WLAN client from the packetizedcommunications includes: extracting MAC addresses from the packetizedcommunications, one of the MAC addresses corresponding to the WLANclient.
 7. The method of claim 1, wherein the step of identifying, bythe multi-layer switch, the WLAN client from the packetizedcommunications is performed substantially in accordance with the RMONEthernet standard.
 8. A multi-layer switch that supports a wired LocalArea Network (wired LAN) having a wired network infrastructure, themulti-layer switch comprising: a high-speed packet data networkinterface that couples the multi-layer switch to a high-speed packetdata network; a port interface communicatively coupled to the high speedpacket data network and to the wired network infrastructure, wherein theport interface further communicatively couples the multi-layer switch toa plurality of Wireless Access Points (WAPs) that couple to the wirednetwork infrastructure; and a processor operably coupled to the portinterface, wherein the processor executes a plurality of softwareinstructions that, upon execution, cause the multi-layer switch to:monitor packetized communications serviced by a WAP of the plurality ofWAPs; identify a Wireless Local Area Network (WLAN) client serviced bythe WAP from the monitored packetized communications; receive anoverloading indication from the WAP; determine that the WLAN clientserviced by the WAP exceeds a usage threshold; and reduce the wirelessbandwidth provided to the WLAN client by the WAP.
 9. The multi-layerswitch of claim 8, wherein the multi-layer switch reduces the wirelessbandwidth provided to the WLAN client by reducing a Class of Service(CoS) provided to the WLAN client by the WAP.
 10. The multi-layer switchof claim 8, wherein the multi-layer switch reduces the wirelessbandwidth provided to the WLAN client by the WAP by introducing roundtrip delay into packetized communications serviced by the multi-layerswitch to reduce the rate at which corresponding higher layercommunication protocols apply data.
 11. The multi-layer switch of claim8, wherein the multi-layer switch determines that the WLAN clientserviced by the WAP exceeds a usage threshold by: determining a usagethreshold for the WLAN client; comparing a current usage level of theWLAN client to the usage level for the WLAN client; and when thecomparison is unfavorable, concluding that the WLAN client serviced bythe WAP exceeds the usage threshold.
 12. The multi-layer switch of claim8, wherein the multi-layer switch identifies the WLAN client by:extracting MAC addresses from the packetized communications, one of theMAC addresses corresponding to the WLAN client.
 13. The multi-layerswitch of claim 8, wherein the multi-layer switch operates substantiallyin accordance with the RMON Ethernet standard.
 14. A combined wiredLocal Area Network (wired LAN) and Wireless Local Area Network (WLAN)the services a plurality of WLAN clients, the combined wired LAN andWLAN comprising: a wired network infrastructure; a plurality of WirelessAccess Points (WAPs) coupled to the wired network infrastructure; amulti-layer switch coupled to the wired network infrastructure; whereina WAP of the plurality of WAPs and the multi-layer switch servicepacketized communications for a plurality of WLAN clients; wherein themulti-layer switch identifies a WLAN client serviced by the WAP from themonitored packetized communications; wherein the multi-layer switchreceives an overloading indication from the WAP; wherein, themulti-layer switch determines that the WLAN client serviced by the WAPexceeds a usage threshold; and wherein the multi-layer switch reducesthe wireless bandwidth provided to the WLAN client by the WAP.
 15. Thecombined wired LAN and WLAN of claim 14, wherein the multi-layer switchreduces the wireless bandwidth provided to the WLAN client by reducing aClass of Service (CoS) provided to the WLAN client by the WAP.
 16. Thecombined wired LAN and WLAN of claim 14, wherein the multi-layer switchreduces the wireless bandwidth provided to the WLAN client byintroducing round trip delay into packetized communications serviced bythe multi-layer switch to reduce the rate at which corresponding higherlayer communication protocols apply data.
 17. The combined wired LAN andWLAN of claim 14, wherein in determining that the WLAN client servicedby the WAP exceeds a usage threshold the multi-layer switch: determinesa usage threshold for the WLAN client; compares a current usage level ofthe WLAN client to the usage level for the WLAN client; and when thecomparison is unfavorable, concludes that the WLAN client serviced bythe WAP exceeds the usage threshold.
 18. The combined wired LAN and WLANof claim 14, further comprising a network manager that: determines ausage threshold for the WLAN client; compares a current usage level ofthe WLAN client to the usage level for the WLAN client; when thecomparison is unfavorable, concludes that the WLAN client serviced bythe WAP exceeds the usage threshold; and reports to the multi-layerswitch that the WLAN client serviced by the WAP exceeds the usagethreshold.
 19. The combined wired LAN and WLAN of claim 14, wherein inidentifying the WLAN client the multi-layer switch: extracts MACaddresses from the packetized communications, one of the MAC addressescorresponding to the WLAN client.
 20. The combined wired LAN and WLAN ofclaim 14, wherein multi-layer switch operates substantially inaccordance with the RMON Ethernet standard.